54份可可种质资源主要品质性状及相关分析

【目的】对54份可可种质材料的主要品质性状进行比较分析，筛选出品质性状优良的种质，为可可新品种培育提供基础材料，也为探究可可品质性状的影响因素提供理论参考。【方法】以来源于不同国家的54份可可种质为材料，采用超声波超离法、气相色谱法和福林酚法测定可可脂、多酚、脂肪酸组分（棕榈酸、硬脂酸、油酸和亚油）含量及脂肪酸总含量，并对其进行变异分析、相关分析及聚类分析。【结果】54份可可种质中，XYS53的可可脂、棕榈酸、硬脂酸、油酸、亚油酸含量及脂肪酸总含量均最低；XYS52的可可脂含量和脂肪酸总含量均最高；XYS18的棕榈酸含量最高；XYS17的硬脂酸含量最高；XYS52的油酸含量最高；XYS44的亚油酸含量最高；XYS20的多酚含量最高。7个品质性状指标的变异系数为11.52%~18.74%，其中棕榈酸、亚油酸和多酚的变异幅度较大，变异系数分别为18.74%、18.62%和14.42%；可可脂含量变异系数最小，为11.52%。可可脂含量与棕榈酸、硬脂酸和油酸含量呈极显著正相关（P<0.01，下同），棕榈酸含量与硬脂酸含量间、棕榈酸含量与油酸含量间及硬脂酸含量与油酸含量间均呈极显著正相关；亚油酸含量与棕榈酸含量存在显著负相关（P<0.05，下同）；多酚含量与可可脂、棕榈酸、硬脂酸、油酸和亚油酸含量均呈负相关，但未达显著水平（P>0.05，下同）。不同国家的可可种质间可可脂、硬脂酸、油酸、多酚含量及脂肪酸总含量无显著差异，但中国与泰国的可可种质间棕榈酸含量和亚油酸含量存在显著差异。主成分分析和聚类分析均发现，归属于类群Ⅰ的15份种质品质性状综合表现较好，且主要来自于中国和越南。【结论】可可种质的主要品质性状与其来源地间存在一定相关性。在可可品种选育过程中，需结合性状间相关性综合考虑可可品质性状表现，可优先选择中国和越南的15个综合性状优良的种质作为育种材料或亲本来培育优良可可品种。

Evaluation and correlation analysis of main quality traits of 54 cacao germplasm resources

【Objective】 In order to select excellent cacao germplasms with better quality traits, evaluation and correlation analysis were performed by 54 cacao core collections. The results could provide basic materials for cultivation of new cacao varieties, and supply a theoretical basis for the formation of cacao quality traits.【Method】 The main quality traits, cocoa butter content, polyphenol, fatty acid components(palmitic acid content, stearic acid content, oleic acid content, linoleic acid) and total content of fatty acids were performed with 54 different origins cacao germplasms from different countries, by ultrasonic ultra-isolation method, gas chromatography and Folin-Ciocalteu's method. Variability analysis, correlation analysis and cluster analysis were also performed.【Result】 Among 54 cacao germplasms, XYS53 showed the lowest cocoa butter content, palmitic acid content, stearic acid content, oleic acid content, linoleic acid content and total fatty acid content. XYS52 showed the highest cocoa butter content and total fatty acid content. XYS18, XYS17, XYS52, XYS44 and XYS20 showed highest phenotype on palmitic acid content, stearic acid content, oleic acid content, linoleic acid content and polyphenol content, respectively. The average of variation coefficient was from 1.52% to 18.74%, of which palmitic acid, linoleic acid and polyphenols showed larger variations with 18.74%, 18.62% and 14.42%. The variation coefficient of cocoa butter content was the smallest(11.52%). Correlation analysis showed that cocoa butter content was extremely significantly positively correlated with palmitic acid, stearic acid and oleic acid(P<0.01, the same below). There was an extremely significant positive correlation between palmitic acid and stearic acid, between palmitic acid and oleic acid, and between stearic acid and oleic acid. There was significant negative correlation between linoleic acid and palmitic acid(P<0.05, the same below). While polyphenols were negatively correlated with cocoa butter, palmitic acid, stearic acid, oleic acid and linoleic acid contents, but did not reach a significant level(P>0.05, the same below). There were no significant differences among cocoa butter content, stearic acid content, oleic acid content, polyphenol content and four fatty acids contents of different germplasm origin countries. However, there were significant differences of palmitic acid and linoleic acid contents between germplasms from China and Thailand. The results of principal component analysis and cluster analysis indicated that quality traits of 15 germplasm belonging to Group I performed well, these germplasms were maily from China and Vietnam.【Conclusion】 There is certain correlation between the main quality traits and different cacao germplasm origins. In the breeding process of selecting cocao varieties, by combining the correlation between traits and comprehensively considering the performance of cocao quality traits, 15 germplasms with excellent comprehensive traits from China and Vietnam can be preferred as breeding materials or parents to cultivate excellent cocao varieties.